In this interview from Greenland, glaciologist Mark Fahnestock describes the roar of a 1000-foot iceberg dropping off the Jakobshavn Isbræ into the Ilulissat Icefjord. Includes time-lapse photography of this massive calving event.

What controls the speed of Greenland’s big outlet glaciers like the Jakobshavn? How do they interact with the climate system? And most importantly, what does the future hold for the glaciers of Greenland? In this video, glaciologist Mark Fahnestock discusses glacier dynamics and what he hopes to learn through his studies.

An interview with Mel Zucker, Professor of Geology, Skyline College, San Bruno, California.

In the early 1900s, German meteorologist Alfred Wegener suggested that the earth's continents were once a single landmass that had somehow split into pieces, drifting their separate ways. Geologists the world over called his idea preposterous. Decades later, their ridicule shifted to admiration as new tools developed by the military to map the ocean floors revealed the engine that drives the continents' movement. Geology professor Mel Zucker tells the story of this brilliant earth scientist and how, long after his death, science finally caught up with Wegener's crazy idea.

It's not enough to know that a nutcracker works; a scientist needs to know why. Historian Richard Carrier recounts how, in ancient Greece, pondering the nutcracker led to the physics of levers. He describes how Aristotle and others shaped the beginnings of Western scientific thought: the notion that knowledge of the natural world relies on being able to question, test, reproduce and improve the accuracy of what's believed to be true. He explains why he sees science as a practice rooted in values, how it protects us from our own erroneous tendencies, and why questioning authority helps foster scientific thinking.

When astronomer Isabel Hawkins began exploring the astronomical work of Native Americans, their knowledge broadened
her view of the night sky. She's since discovered several scientists incorporating the work of native people, both modern and ancient, into their current-day research. Isabel describes how she sees science as a cultural construct, the value of learning from personal experience, and that evidence comes in many forms.

All wound up with nothing to do? Swing by the Exploratorium on September 6th, beginning at 10am, for the 2008 California State Yo-Yo Championships. Meet National and World Yo-Yo Champions, watch daredevil tricks, and learn basic techniques from yo-yo masters. This event is included in the price of admission to the Exploratorium. Registration is open to the public and begins at 10am. Winners will qualify for next year's regional tournament. For more information, go to www.calstateyoyo.com.

The Ice Stories crew caught up with glaciologist Mark Fahnestock on his way back home after a few weeks camping near Greenland's Jakobshavn Isbræ, the most productive and among the fastest-moving glaciers in the world. In this interview, Mark describes some of the physics of this speedy glacier and why so many scientists are interested in studying the dynamics of Jakobshavn.

Webcasts made possible through the generosity of the Gordon and Betty Moore Foundation, the Jim Clark Endowment for Internet Education, the McBean Family Foundation.

Bandwidth and infrastructure support for connectivity to the California Research and Education Network and to other Internet2-connected networks provided by the Corporation for Educational Networks Initiatives in California (CENIC).